/*
 * $Id: rawinflate.js,v 0.2 2009/03/01 18:32:24 dankogai Exp $
 *
 * original:
 * http://www.onicos.com/staff/iz/amuse/javascript/expert/inflate.txt
 */

/* Copyright (C) 1999 Masanao Izumo <iz@onicos.co.jp>
 * Version: 1.0.0.1
 * LastModified: Dec 25 1999
 */

/* Interface:
 * data = inflate(src);
 */

/* constant parameters */
var WSIZE = 32768, // Sliding Window size
	STORED_BLOCK = 0,
	STATIC_TREES = 1,
	DYN_TREES = 2,

/* for inflate */
	lbits = 9, // bits in base literal/length lookup table
	dbits = 6, // bits in base distance lookup table

/* variables (inflate) */
	slide,
	wp, // current position in slide
	fixed_tl = null, // inflate static
	fixed_td, // inflate static
	fixed_bl, // inflate static
	fixed_bd, // inflate static
	bit_buf, // bit buffer
	bit_len, // bits in bit buffer
	method,
	eof,
	copy_leng,
	copy_dist,
	tl, // literal length decoder table
	td, // literal distance decoder table
	bl, // number of bits decoded by tl
	bd, // number of bits decoded by td

	inflate_data,
	inflate_pos,


/* constant tables (inflate) */
	MASK_BITS = [
		0x0000,
		0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
		0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
	],
	// Tables for deflate from PKZIP's appnote.txt.
	// Copy lengths for literal codes 257..285
	cplens = [
		3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
		35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0
	],
/* note: see note #13 above about the 258 in this list. */
	// Extra bits for literal codes 257..285
	cplext = [
		0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
		3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99 // 99==invalid
	],
	// Copy offsets for distance codes 0..29
	cpdist = [
		1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
		257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
		8193, 12289, 16385, 24577
	],
	// Extra bits for distance codes
	cpdext = [
		0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
		7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
		12, 12, 13, 13
	],
	// Order of the bit length code lengths
	border = [
		16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
	];
/* objects (inflate) */

function HuftList() {
	this.next = null;
	this.list = null;
}

function HuftNode() {
	this.e = 0; // number of extra bits or operation
	this.b = 0; // number of bits in this code or subcode

	// union
	this.n = 0; // literal, length base, or distance base
	this.t = null; // (HuftNode) pointer to next level of table
}

/*
	* @param b-  code lengths in bits (all assumed <= BMAX)
	* @param n- number of codes (assumed <= N_MAX)
	* @param s- number of simple-valued codes (0..s-1)
	* @param d- list of base values for non-simple codes
	* @param e- list of extra bits for non-simple codes
	* @param mm- maximum lookup bits
	*/
function HuftBuild(b, n, s, d, e, mm) {
	this.BMAX = 16; // maximum bit length of any code
	this.N_MAX = 288; // maximum number of codes in any set
	this.status = 0; // 0: success, 1: incomplete table, 2: bad input
	this.root = null; // (HuftList) starting table
	this.m = 0; // maximum lookup bits, returns actual

/* Given a list of code lengths and a maximum table size, make a set of
	tables to decode that set of codes. Return zero on success, one if
	the given code set is incomplete (the tables are still built in this
	case), two if the input is invalid (all zero length codes or an
	oversubscribed set of lengths), and three if not enough memory.
	The code with value 256 is special, and the tables are constructed
	so that no bits beyond that code are fetched when that code is
	decoded. */
	var a; // counter for codes of length k
	var c = [];
	var el; // length of EOB code (value 256)
	var f; // i repeats in table every f entries
	var g; // maximum code length
	var h; // table level
	var i; // counter, current code
	var j; // counter
	var k; // number of bits in current code
	var lx = [];
	var p; // pointer into c[], b[], or v[]
	var pidx; // index of p
	var q; // (HuftNode) points to current table
	var r = new HuftNode(); // table entry for structure assignment
	var u = [];
	var v = [];
	var w;
	var x = [];
	var xp; // pointer into x or c
	var y; // number of dummy codes added
	var z; // number of entries in current table
	var o;
	var tail; // (HuftList)

	tail = this.root = null;

	// bit length count table
	for (i = 0; i < this.BMAX + 1; i++) {
		c[i] = 0;
	}
	// stack of bits per table
	for (i = 0; i < this.BMAX + 1; i++) {
		lx[i] = 0;
	}
	// HuftNode[BMAX][]  table stack
	for (i = 0; i < this.BMAX; i++) {
		u[i] = null;
	}
	// values in order of bit length
	for (i = 0; i < this.N_MAX; i++) {
		v[i] = 0;
	}
	// bit offsets, then code stack
	for (i = 0; i < this.BMAX + 1; i++) {
		x[i] = 0;
	}

	// Generate counts for each bit length
	el = n > 256 ? b[256] : this.BMAX; // set length of EOB code, if any
	p = b; pidx = 0;
	i = n;
	do {
		c[p[pidx]]++; // assume all entries <= BMAX
		pidx++;
	} while (--i > 0);
	if (c[0] === n) { // null input--all zero length codes
		this.root = null;
		this.m = 0;
		this.status = 0;
		return;
	}

	// Find minimum and maximum length, bound *m by those
	for (j = 1; j <= this.BMAX; j++) {
		if (c[j] !== 0) {
			break;
		}
	}
	k = j; // minimum code length
	if (mm < j) {
		mm = j;
	}
	for (i = this.BMAX; i !== 0; i--) {
		if (c[i] !== 0) {
			break;
		}
	}
	g = i; // maximum code length
	if (mm > i) {
		mm = i;
	}

	// Adjust last length count to fill out codes, if needed
	for (y = 1 << j; j < i; j++, y <<= 1) {
		if ((y -= c[j]) < 0) {
			this.status = 2; // bad input: more codes than bits
			this.m = mm;
			return;
		}
	}
	if ((y -= c[i]) < 0) {
		this.status = 2;
		this.m = mm;
		return;
	}
	c[i] += y;

	// Generate starting offsets into the value table for each length
	x[1] = j = 0;
	p = c;
	pidx = 1;
	xp = 2;
	while (--i > 0) { // note that i == g from above
		x[xp++] = (j += p[pidx++]);
	}

	// Make a table of values in order of bit lengths
	p = b; pidx = 0;
	i = 0;
	do {
		if ((j = p[pidx++]) !== 0) {
			v[x[j]++] = i;
		}
	} while (++i < n);
	n = x[g]; // set n to length of v

	// Generate the Huffman codes and for each, make the table entries
	x[0] = i = 0; // first Huffman code is zero
	p = v; pidx = 0; // grab values in bit order
	h = -1; // no tables yet--level -1
	w = lx[0] = 0; // no bits decoded yet
	q = null; // ditto
	z = 0; // ditto

	// go through the bit lengths (k already is bits in shortest code)
	for (null; k <= g; k++) {
		a = c[k];
		while (a-- > 0) {
			// here i is the Huffman code of length k bits for value p[pidx]
			// make tables up to required level
			while (k > w + lx[1 + h]) {
				w += lx[1 + h]; // add bits already decoded
				h++;

				// compute minimum size table less than or equal to *m bits
				z = (z = g - w) > mm ? mm : z; // upper limit
				if ((f = 1 << (j = k - w)) > a + 1) { // try a k-w bit table
					// too few codes for k-w bit table
					f -= a + 1; // deduct codes from patterns left
					xp = k;
					while (++j < z) { // try smaller tables up to z bits
						if ((f <<= 1) <= c[++xp]) {
							break; // enough codes to use up j bits
						}
						f -= c[xp]; // else deduct codes from patterns
					}
				}
				if (w + j > el && w < el) {
					j = el - w; // make EOB code end at table
				}
				z = 1 << j; // table entries for j-bit table
				lx[1 + h] = j; // set table size in stack

				// allocate and link in new table
				q = [];
				for (o = 0; o < z; o++) {
					q[o] = new HuftNode();
				}

				if (!tail) {
					tail = this.root = new HuftList();
				} else {
					tail = tail.next = new HuftList();
				}
				tail.next = null;
				tail.list = q;
				u[h] = q; // table starts after link

				/* connect to last table, if there is one */
				if (h > 0) {
					x[h] = i; // save pattern for backing up
					r.b = lx[h]; // bits to dump before this table
					r.e = 16 + j; // bits in this table
					r.t = q; // pointer to this table
					j = (i & ((1 << w) - 1)) >> (w - lx[h]);
					u[h - 1][j].e = r.e;
					u[h - 1][j].b = r.b;
					u[h - 1][j].n = r.n;
					u[h - 1][j].t = r.t;
				}
			}

			// set up table entry in r
			r.b = k - w;
			if (pidx >= n) {
				r.e = 99; // out of values--invalid code
			} else if (p[pidx] < s) {
				r.e = (p[pidx] < 256 ? 16 : 15); // 256 is end-of-block code
				r.n = p[pidx++]; // simple code is just the value
			} else {
				r.e = e[p[pidx] - s]; // non-simple--look up in lists
				r.n = d[p[pidx++] - s];
			}

			// fill code-like entries with r //
			f = 1 << (k - w);
			for (j = i >> w; j < z; j += f) {
				q[j].e = r.e;
				q[j].b = r.b;
				q[j].n = r.n;
				q[j].t = r.t;
			}

			// backwards increment the k-bit code i
			for (j = 1 << (k - 1); (i & j) !== 0; j >>= 1) {
				i ^= j;
			}
			i ^= j;

			// backup over finished tables
			while ((i & ((1 << w) - 1)) !== x[h]) {
				w -= lx[h]; // don't need to update q
				h--;
			}
		}
	}

	/* return actual size of base table */
	this.m = lx[1];

	/* Return true (1) if we were given an incomplete table */
	this.status = ((y !== 0 && g !== 1) ? 1 : 0);
}


/* routines (inflate) */

function GET_BYTE() {
	if (inflate_data.length === inflate_pos) {
		return -1;
	}
	return inflate_data[inflate_pos++] & 0xff;
}

function NEEDBITS(n) {
	while (bit_len < n) {
		bit_buf |= GET_BYTE() << bit_len;
		bit_len += 8;
	}
}

function GETBITS(n) {
	return bit_buf & MASK_BITS[n];
}

function DUMPBITS(n) {
	bit_buf >>= n;
	bit_len -= n;
}

function inflate_codes(buff, off, size) {
	// inflate (decompress) the codes in a deflated (compressed) block.
	// Return an error code or zero if it all goes ok.
	var e; // table entry flag/number of extra bits
	var t; // (HuftNode) pointer to table entry
	var n;

	if (size === 0) {
		return 0;
	}

	// inflate the coded data
	n = 0;
	for (;;) { // do until end of block
		NEEDBITS(bl);
		t = tl.list[GETBITS(bl)];
		e = t.e;
		while (e > 16) {
			if (e === 99) {
				return -1;
			}
			DUMPBITS(t.b);
			e -= 16;
			NEEDBITS(e);
			t = t.t[GETBITS(e)];
			e = t.e;
		}
		DUMPBITS(t.b);

		if (e === 16) { // then it's a literal
			wp &= WSIZE - 1;
			buff[off + n++] = slide[wp++] = t.n;
			if (n === size) {
				return size;
			}
			continue;
		}

		// exit if end of block
		if (e === 15) {
			break;
		}

		// it's an EOB or a length

		// get length of block to copy
		NEEDBITS(e);
		copy_leng = t.n + GETBITS(e);
		DUMPBITS(e);

		// decode distance of block to copy
		NEEDBITS(bd);
		t = td.list[GETBITS(bd)];
		e = t.e;

		while (e > 16) {
			if (e === 99) {
				return -1;
			}
			DUMPBITS(t.b);
			e -= 16;
			NEEDBITS(e);
			t = t.t[GETBITS(e)];
			e = t.e;
		}
		DUMPBITS(t.b);
		NEEDBITS(e);
		copy_dist = wp - t.n - GETBITS(e);
		DUMPBITS(e);

		// do the copy
		while (copy_leng > 0 && n < size) {
			copy_leng--;
			copy_dist &= WSIZE - 1;
			wp &= WSIZE - 1;
			buff[off + n++] = slide[wp++] = slide[copy_dist++];
		}

		if (n === size) {
			return size;
		}
	}

	method = -1; // done
	return n;
}

function inflate_stored(buff, off, size) {
	/* "decompress" an inflated type 0 (stored) block. */
	var n;

	// go to byte boundary
	n = bit_len & 7;
	DUMPBITS(n);

	// get the length and its complement
	NEEDBITS(16);
	n = GETBITS(16);
	DUMPBITS(16);
	NEEDBITS(16);
	if (n !== ((~bit_buf) & 0xffff)) {
		return -1; // error in compressed data
	}
	DUMPBITS(16);

	// read and output the compressed data
	copy_leng = n;

	n = 0;
	while (copy_leng > 0 && n < size) {
		copy_leng--;
		wp &= WSIZE - 1;
		NEEDBITS(8);
		buff[off + n++] = slide[wp++] = GETBITS(8);
		DUMPBITS(8);
	}

	if (copy_leng === 0) {
		method = -1; // done
	}
	return n;
}

function inflate_fixed(buff, off, size) {
	// decompress an inflated type 1 (fixed Huffman codes) block.  We should
	// either replace this with a custom decoder, or at least precompute the
	// Huffman tables.

	// if first time, set up tables for fixed blocks
	if (!fixed_tl) {
		var i; // temporary variable
		var l = []; // 288 length list for huft_build (initialized below)
		var h; // HuftBuild

		// literal table
		for (i = 0; i < 144; i++) {
			l[i] = 8;
		}
		for (null; i < 256; i++) {
			l[i] = 9;
		}
		for (null; i < 280; i++) {
			l[i] = 7;
		}
		for (null; i < 288; i++) { // make a complete, but wrong code set
			l[i] = 8;
		}
		fixed_bl = 7;

		h = new HuftBuild(l, 288, 257, cplens, cplext, fixed_bl);
		if (h.status !== 0) {
			console.error("HufBuild error: " + h.status);
			return -1;
		}
		fixed_tl = h.root;
		fixed_bl = h.m;

		// distance table
		for (i = 0; i < 30; i++) { // make an incomplete code set
			l[i] = 5;
		}
		fixed_bd = 5;

		h = new HuftBuild(l, 30, 0, cpdist, cpdext, fixed_bd);
		if (h.status > 1) {
			fixed_tl = null;
			console.error("HufBuild error: " + h.status);
			return -1;
		}
		fixed_td = h.root;
		fixed_bd = h.m;
	}

	tl = fixed_tl;
	td = fixed_td;
	bl = fixed_bl;
	bd = fixed_bd;
	return inflate_codes(buff, off, size);
}

function inflate_dynamic(buff, off, size) {
	// decompress an inflated type 2 (dynamic Huffman codes) block.
	var i; // temporary variables
	var j;
	var l; // last length
	var n; // number of lengths to get
	var t; // (HuftNode) literal/length code table
	var nb; // number of bit length codes
	var nl; // number of literal/length codes
	var nd; // number of distance codes
	var ll = [];
	var h; // (HuftBuild)

	// literal/length and distance code lengths
	for (i = 0; i < 286 + 30; i++) {
		ll[i] = 0;
	}

	// read in table lengths
	NEEDBITS(5);
	nl = 257 + GETBITS(5); // number of literal/length codes
	DUMPBITS(5);
	NEEDBITS(5);
	nd = 1 + GETBITS(5); // number of distance codes
	DUMPBITS(5);
	NEEDBITS(4);
	nb = 4 + GETBITS(4); // number of bit length codes
	DUMPBITS(4);
	if (nl > 286 || nd > 30) {
		return -1; // bad lengths
	}

	// read in bit-length-code lengths
	for (j = 0; j < nb; j++) {
		NEEDBITS(3);
		ll[border[j]] = GETBITS(3);
		DUMPBITS(3);
	}
	for (null; j < 19; j++) {
		ll[border[j]] = 0;
	}

	// build decoding table for trees--single level, 7 bit lookup
	bl = 7;
	h = new HuftBuild(ll, 19, 19, null, null, bl);
	if (h.status !== 0) {
		return -1; // incomplete code set
	}

	tl = h.root;
	bl = h.m;

	// read in literal and distance code lengths
	n = nl + nd;
	i = l = 0;
	while (i < n) {
		NEEDBITS(bl);
		t = tl.list[GETBITS(bl)];
		j = t.b;
		DUMPBITS(j);
		j = t.n;
		if (j < 16) { // length of code in bits (0..15)
			ll[i++] = l = j; // save last length in l
		} else if (j === 16) { // repeat last length 3 to 6 times
			NEEDBITS(2);
			j = 3 + GETBITS(2);
			DUMPBITS(2);
			if (i + j > n) {
				return -1;
			}
			while (j-- > 0) {
				ll[i++] = l;
			}
		} else if (j === 17) { // 3 to 10 zero length codes
			NEEDBITS(3);
			j = 3 + GETBITS(3);
			DUMPBITS(3);
			if (i + j > n) {
				return -1;
			}
			while (j-- > 0) {
				ll[i++] = 0;
			}
			l = 0;
		} else { // j === 18: 11 to 138 zero length codes
			NEEDBITS(7);
			j = 11 + GETBITS(7);
			DUMPBITS(7);
			if (i + j > n) {
				return -1;
			}
			while (j-- > 0) {
				ll[i++] = 0;
			}
			l = 0;
		}
	}

	// build the decoding tables for literal/length and distance codes
	bl = lbits;
	h = new HuftBuild(ll, nl, 257, cplens, cplext, bl);
	if (bl === 0) { // no literals or lengths
		h.status = 1;
	}
	if (h.status !== 0) {
		if (h.status !== 1) {
			return -1; // incomplete code set
		}
		// **incomplete literal tree**
	}
	tl = h.root;
	bl = h.m;

	for (i = 0; i < nd; i++) {
		ll[i] = ll[i + nl];
	}
	bd = dbits;
	h = new HuftBuild(ll, nd, 0, cpdist, cpdext, bd);
	td = h.root;
	bd = h.m;

	if (bd === 0 && nl > 257) { // lengths but no distances
		// **incomplete distance tree**
		return -1;
	}
/*
	if (h.status === 1) {
		// **incomplete distance tree**
	}
*/
	if (h.status !== 0) {
		return -1;
	}

	// decompress until an end-of-block code
	return inflate_codes(buff, off, size);
}

function inflate_start() {
	if (!slide) {
		slide = []; // new Array(2 * WSIZE); // slide.length is never called
	}
	wp = 0;
	bit_buf = 0;
	bit_len = 0;
	method = -1;
	eof = false;
	copy_leng = copy_dist = 0;
	tl = null;
}

function inflate_internal(buff, off, size) {
	// decompress an inflated entry
	var n, i;

	n = 0;
	while (n < size) {
		if (eof && method === -1) {
			return n;
		}

		if (copy_leng > 0) {
			if (method !== STORED_BLOCK) {
				// STATIC_TREES or DYN_TREES
				while (copy_leng > 0 && n < size) {
					copy_leng--;
					copy_dist &= WSIZE - 1;
					wp &= WSIZE - 1;
					buff[off + n++] = slide[wp++] = slide[copy_dist++];
				}
			} else {
				while (copy_leng > 0 && n < size) {
					copy_leng--;
					wp &= WSIZE - 1;
					NEEDBITS(8);
					buff[off + n++] = slide[wp++] = GETBITS(8);
					DUMPBITS(8);
				}
				if (copy_leng === 0) {
					method = -1; // done
				}
			}
			if (n === size) {
				return n;
			}
		}

		if (method === -1) {
			if (eof) {
				break;
			}

			// read in last block bit
			NEEDBITS(1);
			if (GETBITS(1) !== 0) {
				eof = true;
			}
			DUMPBITS(1);

			// read in block type
			NEEDBITS(2);
			method = GETBITS(2);
			DUMPBITS(2);
			tl = null;
			copy_leng = 0;
		}

		switch (method) {
		case STORED_BLOCK:
			i = inflate_stored(buff, off + n, size - n);
			break;

		case STATIC_TREES:
			if (tl) {
				i = inflate_codes(buff, off + n, size - n);
			} else {
				i = inflate_fixed(buff, off + n, size - n);
			}
			break;

		case DYN_TREES:
			if (tl) {
				i = inflate_codes(buff, off + n, size - n);
			} else {
				i = inflate_dynamic(buff, off + n, size - n);
			}
			break;

		default: // error
			i = -1;
			break;
		}

		if (i === -1) {
			if (eof) {
				return 0;
			}
			return -1;
		}
		n += i;
	}
	return n;
}

export function inflate(arr) {
	var buff = [], i;

	inflate_start();
	inflate_data = arr;
	inflate_pos = 0;

	do {
		i = inflate_internal(buff, buff.length, 1024);
	} while (i > 0);
	inflate_data = null; // G.C.
	return buff;
}